The present invention relates to a jet device for depositing fluid drops upon a moving fluid receiving medium and, more particularly, to such a device for use in applying precisely controlled quantities of dye to a moving textile or fabric web.
In the textile industry, colored fabric material is typically produced by first weaving or otherwise manufacturing a web of fabric material from uncolored stock and, thereafter, applying a liquid dye to the fabric web. The wet fabric web is then dried to produce the finished colored fabric stock.
In one conventional dyeing technique, fabric web is transported through a bath of liquid dye. Thereafter, excess dye is removed from the web by passing it between a series of squeeze rollers. Dyeing a fabric web in this manner, however, presents several problems. After the dye drenched web passes between the squeeze rollers, the dye tends to migrate through the web fibers, producing uneven accumulation of dye across the web, and thus resulting in non-uniform coloration.
Additionally, since the web passes through a dye bath and absorbs a large quantity of dye per unit area, it is necessary to maintain a relatively diluted dye bath solution. If a higher concentration of dye in the bath solution were to be used, too great a quantity of dye would be applied per unit area of the web. Since, however, a substantial quantity of liquid is absorbed by the web as it passes through the dilute dye bath, this liquid must be removed thereafter from the web in a drying process, typically by application of heat energy to the web. As will be appreciated, such a drying operation is costly, since substantial amounts of energy are required.
Another dyeing technique for fabric webs which has been utilized in the past is to spray liquid dye from one or more spray nozzles onto the moving web. U.S. Pat. No. 3,271,102, issued Sept. 6, 1966, to Morgan, shows a spray apparatus for dyeing pile carpeting. An arrangement is described in which the fabric web is transported around a relatively sharp corner, thus opening the pile to permit all portions of the pile to receive the liquid dye.
U.S. Pat. No. 2,532,471, issued Dec. 5, 1950, to Wedler, discloses a similar spray applicator in which liquid dye is applied to a fabric web by means of a plurality of spray nozzles positioned in a spray chamber through which the web passes. After passing through several subsequent treatment chambers, the dyed web is transported through a drying chamber in which the fabric is dried by means of hot air jets.
Finally, U.S. Pat. No. 2,804,764, issued Sept. 3, 1957, to Runton, discloses an apparatus for dyeing a yarn sheet which is to be wound on a warp beam for use on a velvet loom. A plurality of separate spray nozzles are positioned in a series of rows which are inclined with respect to the direction of movement of the yarn sheet. The nozzles may be individually controlled to form a desired pattern on the yarn sheet. The sheet is then passed under a dryer, such as a bank of infrared lamps, to dry and set the dye. While permitting the application of a higher concentration dye solution to the web such that the amount of subsequent drying is reduced than techniques in which the web is dipped in a dye bath, the Morgan, Wedler, and Runton dye spraying devices are somewhat limited in that the amount of dye applied to the web per unit length can be controlled with less precision than is desired. Additionally since the spray nozzles provide a relatively constant spray of fluid dye, fluctuations in the speed of movement of the web result in uneven application of dye to the web.
U.S. Pat. No. 3,443,878, issued May 13, 1969, to Weber et al, discloses a device for continuously dyeing a textile web in which a more precisely controlled by application of dye to the fabric web may be obtained. One embodiment of the Weber et al 3,443,878 device utilizes an air jet which deflects a stream of dye produced by a nozzle such that the dye is controllably applied to the web. A number of such nozzles and air jets may be provided. In another embodiment, air nozzles are utilized to deflect portions of a curtain of liquid dye onto the web which moves past the curtain. Although the Weber et al 3,443,878 patent mentions that dye streams may be deflected by a force field other than that produced by an air nozzle (such as an electromagnetic or electrostatic field), all of the embodiments disclosed in the Weber et al patent utilize air nozzles for stream deflection. While the Weber et al disclosure teaches a dye spraying technique in which intermittent spraying can be accomplished at relatively high speed, the Weber et al device, like the other spray dyeing devices discussed previously is limited in the uniformity with which dye may be applied to the textile web. Additionally, since the spray nozzles of the Weber et al device are operated in a binary manner, that is, either "on" or "off", the Weber et al device does not enable the amount of liquid dye deposited on the fabric web to be with acceptable precision.
Accordingly, it is seen that there is a need for a jet device for depositing fluid, such as dye, on a moving fluid receiving medium in which the number and positioning of the drops so deposited may be controlled precisely.